Descriptive Variables Research Articles

Modelling the leaping cycle by modified Lotka-Volterra equations with applications to technology and safety

ABSTRACT A bounded version of the Lotka – Volterra model based on logistic differential equations is suggested to emulate cyclic behaviour in complex evolutionary and other systems. The model provides reasonable approximations for the so-called leaping cycles and other oscillational processes when the main state variables are limited by physical constraints. The model represents a basic model-building block that can be used in system dynamics and other frameworks and applications that require fundamental understanding and modelling of principal features of complex cyclic processes. Two application areas – technological progress and industrial safety – are specifically considered here. The model is shown to emulate techno-economic cycles reasonably well and give an appropriate qualitative description of risk and safety variations in the industrial environment. Simulations using the suggested model are quantitatively compared with the results of agent-based simulations. While a simple model cannot match all details of complex agent-based simulations of the risk and benefit dilemma, the bounded Lotka – Volterra model still gives a reasonable approximation of the process. The conceptual implications of the model are, nevertheless, significant, pointing to common cyclic mechanisms taking place in complex evolutionary systems that may belong to different branches of science.

Evaluating Staff Attitudes, Intentions, and Behaviors Related to Cyber Security in Large Australian Health Care Environments: Mixed Methods Study.

Previous studies have identified that the effective management of cyber security in large health care environments is likely to be significantly impacted by human and social factors, as well as by technical controls. However, there have been limited attempts to confirm this by using measured and integrated studies to identify specific user motivations and behaviors that can be managed to achieve improved outcomes. This study aims to document and analyze survey and interview data from a diverse range of health care staff members, to determine the primary motivations and behaviors that influence their acceptance and application of cyber security messaging and controls. By identifying these issues, recommendations can be made to positively influence future cyber security governance in health care. An explanatory sequential mixed methods approach was undertaken to analyze quantitative data from a web-based staff survey (N=103), with a concurrent qualitative investigation applied to data gathered via in-depth staff interviews (N=9). Data from both stages of this methodology were mapped to descriptive variables based on a modified version of the Technology Acceptance Model (TAM; TAM2). After normalization, the quantitative data were verified and analyzed using descriptive statistics, distribution and linearity measures, and a bivariate correlation of the TAM variables to identify the Pearson coefficient (r) and significance (P) values. Finally, after confirming Cronbach α, the determinant score for multicollinearity, and the Kaiser-Meyer-Olkin measure, and applying the Bartlett test of sphericity (χ2), an exploratory factor analysis (EFA) was conducted to identify the primary factors with an eigenvalue (λ) >1.0. Comments captured during the qualitative interviews were coded using NVivo software (QSR International) to create an emic-to-etic understanding, which was subsequently integrated with the quantitative results to produce verified conclusions. Using the explanatory sequential methodology, this study showed that the perceived usefulness of security controls emerged as the most significant factor influencing staff beliefs and behaviors. This variable represented 24% of all the variances measured in the EFA and was also the most common category identified across all coded interviews (281/692, 40.6%). The word frequency analysis showed that systems, patients, and people represented the top 3 recurring themes reported by the interviewees. To improve cyber security governance in large health care environments, efforts should be focused on demonstrating how confidentiality, integrity, availability, policies, and cloud or vendor-based controls (the main contributors of usefulness measured by the EFA) can directly improve outcomes for systems, staff, and patients. Further consideration also needs to be given to how clinicians should share data and collaborate on patient care, with tools and processes provided to support and manage data sharing securely and to achieve a consistent baseline of secure and normalized behaviors.

A Meta-Analysis of the Graduated Guidance Procedure

We conducted a descriptive analysis and meta-analysis of single-case research design (SCRD) studies investigating the effectiveness of the graduated guidance procedure. Once we identified studies through electronic databases and reference lists, we used What Works Clearinghouse (WWC) Standards to evaluate each study. Then, we described studies in terms of various descriptive variables, calculated effect sizes through three non-parametric effect size methods, and analyzed results across studies. Results showed 11 of the 27 studies met WWC Standards or met standards with reservation. Of the 11, seven studies resulted in a large effect. We found the graduated guidance procedure to be an evidence-based practice when evaluating the findings against contemporary evidence standards. However, this review also showed that the majority of the reviewed studies ( n = 20) had no effects and only one third of the studies had moderate or strong effects. Implications for researchers and practitioners are discussed.

Ocular and systemic associations and heritability of retinal arterial wall-to-lumen ratios in a twin cohort.

To investigate ocular and systemic factors associated with the retinal arterial wall-to-lumen ratio (WLR) and to determine the relative contribution of genetic and environmental variation to WLR in healthy adults. This cross-sectional twin study included 78 monozygotic and 67 dizygotic same-sex twin pairs aged 58.4 ± 9.8 (mean ± SD) years. Lumen diameter (LD) and outer diameter (OD) of a superotemporal retinal artery were measured using adaptive optics fundus photography, and the WLR was calculated. Linear mixed model regression analysis of associations with WLR comprised the descriptive variables ocular axial length (AL), intraocular pressure (IOP), height, weight, body mass index (BMI), smoking, blood pressure, high density (HDL), low density (LDL) and very low density (VLDL) lipoproteins, total cholesterol and triglycerides. The relative influence of genes and environment on WLR was calculated through polygenetic modelling. Increasing age and arterial blood pressure were associated with a higher WLR, while increasing retinal artery OD and ocular AL were associated with a lower WLR. Sex, smoking status, BMI, IOP, cholesterol levels or triglycerides had no detectable impact on the WLR. Broad-sense heritability of WLR was 21% (95% CI: 1-41%), while environmental factors accounted for the remaining 79% of the interindividual variance (95% CI: 59-99%). Retinal artery wall thickness was closely linked to increasing age and higher arterial blood pressure, the latter being mediated by the environment over genes.

The Use of Urinary Bladder Matrix for Reconstructing Avulsed Traumatic Soft Tissue Injuries to the Maxillofacial Region.

The purpose of the study was to provide an overview of our initial experience utilizing urinary bladder matrix (UBM) for reconstructing avulsed injuries resulting from trauma. This retrospective case series evaluated patients presented with avulsed soft tissue injuries to the head and neck who underwent reconstruction with UBM. Patients were treated by Oral and Maxillofacial Surgery Service in Louisiana State University Health Sciences Center (Baton Rouge, LA). Descriptive variables were collected. Descriptive statistics were calculated. Eight patients (mean age 55.8y) met our inclusion criteria. Wounds were located in the scalp (n=2, 25%), mandible (n=2, 25%), upper eyelid (n=1, 12.5%), cheek (n=1, 12.5%), nose (n=1, 12.5%), or neck (n=1, 12.5%). The depth of the wound extended from the skin to the subcutaneous tissue (n=1, 12.5%), muscle (n=2, 25%), bone (n=3, 37.5%), and/or cartilage (n=1, 12.5%). The mean wound diameter was 47.9cm 2 (range 17-85cm 2 ). Wounds were classified as acute (n=6, 75%) or chronic wounds (n=2, 25%). At 6 months, all patients had achieved complete healing with no need for additional surgical procedures (n=8, 100%) with a mean healing time of 36.5 days (range 14-90d). Urinary bladder matrix minimize donor-side morbidity, eliminates contraction, and offers a wide range of product sizes to cover a wide range of maxillofacial soft tissue defects in a single-stage manner.

Development of associational fiber tracts in fetal human brain: a cadaveric laboratory investigation.

The advent of diffusion tensor imaging (DTI) in addition to cadaveric brain dissection allowed a comprehensive description of an adult human brain. Nonetheless, the knowledge of the development of the internal architecture of the brain is mostly incomplete. Our study aimed to provide a description of the anatomical variations of the major associational bundles, among fetal and early post-natal periods. Seventeen formalin-fixed fetal human brains were enrolled for sulci analysis, and 13 specimens were dissected under the operating microscope, using Klingler's technique. Although fronto-temporal connections could be observed in all stages of development, a distinction between the uncinate fascicle, and the inferior fronto-occipital fascicle was clear starting from the early preterm period (25-35 post-conceptional week). Similarly, we were consistently able to isolate the periatrial white matter that forms the sagittal stratum (SS), with no clear distinction among SS layers. Arcuate fascicle and superior longitudinal fascicle were isolated only at the late stage of development without a reliable description of their entire course. The results of our study demonstrated that, although white matter is mostly unmyelinated among fetal human brains, cadaveric dissection can be performed with consistent results. Furthermore, the stepwise development of the associational fiber tracts strengthens the hypothesis that anatomy and function run in parallel, and higher is the cognitive functions subserved by an anatomical structure, later the development of the fascicle. Further histological-anatomical-DWI investigations are required to appraise and explore this topic.

Does It Matter How the Rigor of High School Coursework Is Measured? Gaps in Coursework Among Students and Across Grades

AbstractResearch shows that the intensity of high school course‐taking is related to postsecondary outcomes. However, there are various approaches to measuring the intensity of students’ course‐taking. This study presents new measures of coursework intensity that rely on differing levels of quantity and quality of coursework. We used these new indices to provide a current description of variations in high school course‐taking across grades and student subgroups using a nationally representative dataset, the High School Longitudinal Study of 2009. Results showed that for measures emphasizing the quality of coursework the gaps in coursework among underserved students were larger and there was less upward movement in rigor across grades.

Assessing Thrombocytopenia and Chronic Liver Disease in Southeast Asia: A Multicentric Cross-Sectional Study.

Background This multicentric cross-sectional study aimed to examine the prevalence of thrombocytopenia (TCP) and investigate the various causes of chronic liver disease (CLD) across 15 Southeast Asian (India, Pakistan, and Bangladesh) tertiary care centers over a three-month period. The study focused on assessing the fibrosis index (FI) and Model for End-Stage Liver Disease (MELD)-sodium (Na) score's capacity to grade and predict the progression and outcomes of patients with already diagnosed CLD. Methods The cross-sectional study enrolled 377 CLD patients. The study utilized admission registries from 15 tertiary care hospitals in Southeast Asia, spanning from April 2023 to June 2023. Various descriptive variables were collected, including gender, tobacco use (specifically, chewed tobacco), underlying etiology, presence of anemia, leukopenia, pancytopenia, infectious state, and liver cirrhosis diagnosed via traditional ultrasonography. This study examined liver failure indicators, including alanine transaminase levels, compensation status, TCP, and liver transplant (LT) listing. The MELD-Na score was the focus of frequency and percentage analysis. MELD-Na and FI medians and standard deviations were provided. Results The study of 377 patients with CLDfound that TCP was present in 4% of patients and leukopenia was present in 12% of patients. The risk of TCP was significantly higher in leukopenic patients (89.5%) than in non-leukopenic patients (52.5%) (p = 0.003). The most common CLD cause was undiagnosable (31%), followed by autoimmune (26%), hepatitis C virus (21%), hepatitis B virus (14%), and schistosomiasis (8%). The majority of patients (98%) had decompensated liver disease. Of the patients,64% had TCP, while 36% did not. The illness severity indicators MELD score and FI had mean ± SD values of 16.89 ± 6.42 and 4.1 ± 1.06, respectively. Similarly, the prevalence of LTneeds among traditional ultrasonography-diagnosed cirrhotic patients was 83.1%, compared to 59.6% among non-cirrhotic patients (p = 0.001). Conclusion Leukopenia and TCP may be linked, which may affect CLD treatment and prognosis in this population.Non-invasive indicators like the FI and MELD-Na score can detect liver fibrosis and severity without invasive procedures, enhancing patient management. These findings highlight the need to improve early diagnosis methods for CLD in Southeast Asia and raise awareness among clinicians about effective diagnostic strategies for non-infectious causes of CLD.

An insight from National Family Health Surveys on changing trends in prevalence and knowledge regarding T.B. in India

Background/objectivesAddressing gaps in knowledge about T.B. is a vital component of T.B.'s elimination to achieve the End T.B. strategy by 2025 in India. The present study compares the correct knowledge regarding T.B. by analysis of the nationally-representative secondary data of NFHS-4 (2015–16) and NFHS-5 (2019–20) data in India. MethodsNFHS-4 and NFHS-5 secondary data on eleven T.B.-related questions analysis was done after seeking permission to use datasets from the Demographic and Health Surveys (DHS) program—sociodemographic details and Responses exported and analysed using M.S. Excel. Descriptive variables were represented as frequency and percentages. Z tests for proportions were used to compare and determine differences between NFHS-4 and NFHS-5 knowledge. Statistical significance was set at a p-value of <0.05. ResultsThe correct knowledge regarding T.B. significantly rose from 457,399 (56.3%) in NFHS-4 to 507,517 (61.4%) in NFHS-5. However, a significant increase in incorrect knowledge about the other modes of transmission of T.B. and T.B. courtesy stigma in households from 95,985 (13.4%) in 2015-16 to 113,978 (14.9%) in 2019-20 was observed. ConclusionsThe correct knowledge of T.B. has significantly increased from NFHS-4 (2015–16) to NFHS-5 (2019–20). However, there is a significant increase in incorrect knowledge regarding the modes of transmission and stigmatising attitudes towards T.B. through improvement in the communication efforts in the National T.B. Elimination Programme (NTEP).

Least-action variational continuum description of Darcian permeation of liquids and gases through stone materials

Watertightness of natural or artificial stone materials, like trap rock or concrete, is a basic property for assessing durability of the built heritage to weathering exposure. Fundamental research of the past century has shown that a reliable experimental determination of intrinsic permeability in stone materials can be achieved by uniaxial water-permeation tests under open-flow conditions, together with the opportunity of employing air permeation tests in place of water-tests to obtain important additional information on a given stone material. Correlations of practical relevance in such laboratory applications, among inlet pressure, outlet pressure and flow rate, stem all from solutions to the general continuum modelling problem of the permeation through a non-deformable homogeneous filter of an incompressible or compressible fluid under stationary uniaxial conditions. The present study addresses such class of mechanical problems on a theoretical variational basis to infer general correlations of practical relevance in permeability testing with a specific consideration of applications in which air-permeability testing combined with use of thinner filters makes the hypothesis of isothermal process in the permeating gas not straightforwardly applicable.

Effects of a proprioceptive focal stimulation (Equistasi®) on reducing the biomechanical risk factors associated with ACL injury in female footballers.

Football presents a high rate of lower limb injuries and high incidence of Anterior Cruciate Ligament (ACL) rupture, especially in women. Due to this there is the need to optimize current prevention programs. This study aims to verify the possibility to reduce the biomechanical risk factors associated with ACL injury, through the application of proprioceptive stimulation by means of the Equistasi® device. Ten elite female footballers were enrolled and received the device for 4 weeks (5 days/week, 1h/day). Athletes were assessed directly on-field at four time points: T0 and T1 (evaluation without and with the device), T2 (after 2 weeks), T4 (after 4 weeks) while performing two different tasks: Romberg Test, and four sidestep cutting maneuvers bilaterally. Seven video cameras synchronized with a plantar pressure system were used, thirty double colored tapes were applied on anatomical landmarks, and three dimensional coordinates reconstructed. Vertical ground reaction forces and center of pressure data were extracted from the plantar pressure insoles. Hip, knee, and ankle flexion-extension angles and moments were computed as well as abd-adduction joint torques. From the Romberg Test both center of pressure descriptive variables and frequency analysis parameters were extracted. Each variable was compared among the different time frames, T1, T2 and T4, through Friedman Test for non-parametric repeated measures (p<0.05); Wilcoxon Signed Rank Test was used for comparing variables between T0 and T1 (p<0.05) and across the different time frames as follows: T1-T2, T2-T4 and T1-T4. Statistically significant differences in both posturographic and biomechanical variables between the assessment at T0 and T1 were detected. Reduced hip and knee abduction torques were revealed in association with reduced both ground reaction forces and ankle dorsiflexion torque from T1 up to T4. The proprioceptive stimuli showed to have the potential to improve cutting biomechanics mainly with respect to the ligament and quadriceps dominance theories. Results of the present study, even if preliminary and on a small sample size, could be considered promising towards the inclusion of proprioceptive training in injury prevention programs.

Three-dimensional metamaterials exhibiting extreme isotropy and negative Poisson's ratio

This research will develop a new set of mechanical metamaterials with simultaneous ideal elastic isotropy and extreme negative Poisson's ratio through a topology optimization approach. Firstly, we propose a new method to generate a three-dimensional ground structure with geometric cubic symmetry. Secondly, a more efficient topology optimization method is developed by utilizing a small number of both integer and continuous design variables for topological description of the design based on the discrete ground structure. Thirdly, two new geometric constraints are incorporated into the mathematical formulation to ensure creation of designs that are practical. Finally, the genetic algorithm is used to solve this type of mixed-integer programming problems. Several numerical examples have been used to demonstrate the generation of a series of three-dimensional microarchitectures from a single integrated design. The microlattices can also be customized to obtain a broad range of negative Poisson's ratios across different relative densities. The effective material properties and macroscopic deformation behaviors of the designs are numerically validated using commercial software.

Mental Health among Automobile industry workers in Chennai – A Cross-sectional study from a Single Industrial unit

Introduction: Working in a mentally healthy place is necessary for people. Adverse mental health conditions can lead to disruption in work which in turn causes absenteeism, low productivity, and financial constraints. This study intends to assess the levels of depression, anxiety and stress and to determine its associated factors among the workers in the automobile industry in Chennai. Methods: A cross-sectional study was conducted among 227 Automobile industry workers in Chennai, India. A semi-structured questionnaire was used to collect information about the socio-demographic and working details of the study subjects, while the Depression Anxiety Stress Scale (DASS -21) was used to assess mental health status. Descriptive variables were expressed as proportions, while Pearson's Chi-square test was used to study the association between dependent and independent variables. Results: A total number of 227 participants were included in the study. More than 80 % of the workers were permanent employees. The prevalence of Depression, anxiety and stress among the study subjects are 38.8%, 43.6 % and 26.9 %, respectively. Workers in the middle age group of 30- 39 years had a higher risk of developing depression, anxiety, and stress than those in the other age groups. For Depression, age, type of family, employment status, and working experience were statistically significant (p&lt;0.05). The sleeping hours, comorbidities, substance use, co-worker support, and supervisor support of the workers were the factors that showed no association with Depression, anxiety, and stress. Conclusion: There is a need for attention to be paid to the development of a healthy psychosocial workplace climate which should be supported by stronger workplace support.

Musculoskeletal injury prevalence in professional padel players. A retrospective study of the 2021 season

ObjectivesTo investigate the influence of the gender, ranking and playing position on the musculoskeletal injuries in professional padel players. DesignAn epidemiological, observational, descriptive, retrospective cross-sectional study. Participants44 injuries were reported by 36 players (20 men/16 women) who participated in the World Padel Tour 2021. SettingOnline questionnaire. Main outcome measureDescriptive statistics and injury prevalence were calculated. Spearman/Pearson correlations between sample characteristics and injury variables were calculated. The chi-square test was used to analyse the association between injury and descriptive variables. A Mann-Whitney U test was performed to compare the group differences with regard to days of absence. ResultsThe results showed different injury prevalence (x1000 matches) in male (10.50) and female players (15.10). A higher injury incidence in top-ranked players, both in male (44.40%) and female (58.33%) was identified, but the low-ranked players reported more severe injuries (>28 days) (p < 0.05). Top-ranked players suffered more muscle injuries (p < 0.01) and low-ranked players suffered more tendon injuries (p < 0.01). Gender, ranking and playing position did not influence the days of absence (p > 0.05). ConclusionsThis study confirms that gender and ranking position had an impact on the injury prevalence in professional padel players.

Prevalence of LTBI in patients with autoimmune diseases and accuracy of IGRA in predicting TB relapse.

The current study evaluated latent tuberculosis infection (LTBI) positivity in a cohort of Indian subjects and the accuracy of IFN-gamma release assay (IGRA) in predicting tuberculosis (TB) reactivation. This cross-sectional, retrospective chart-based study considered patients diagnosed with autoimmune rheumatic diseases (AIRDs), especially those who received treatment with biologics or targeted synthetic (ts)DMARDs. The patients had undergone LTBI screening and IGRA test. The study excluded patients with inadequate information and those who had undergone test exclusively for diagnostic purpose. Statistical analyses were carried out for descriptive, demographic and clinical variables. Accuracy and error rate in predicting the absence of TB reactivation were calculated for IGRA test. The study selected 943 patients who had undergone IGRA pre-screening prior to the initiation of biologics or tsDMARDs with a mean age of 42.93 ± 14.01 years and male-to-female ratio of 1:2.08. RA was the most common primary diagnosis (43.16%). The proportion of subjects who received single, double and triple or more DMARDs or immune suppressants were 54.35%, 33.33% and 7.69%, respectively. Among the selected subjects, 125 patients were LTBI positive and 816 were negative. All patients, except one who tested positive at baseline, received antitubercular prophylaxis. Accuracy of IGRA in predicting the absence of TB reactivation was 99.6%, with an error rate of 0.46. LTBI screening is beneficial in AIRDs patients prior to the prescription of biologics or tsDMARDs. IGRA is ideal for identifying patients with increased likelihood of developing TB upon receiving biologics or tsDMARDs with reasonable accuracy.

Understanding time-to-recovery among Guatemalan Children before and during COVID-19

PurposeTo understand malnutrition recovery at a Guatemalan Nutrition Rehabilitation Center (NRC) before and during the COVID-19 pandemic. Design and methodsA retrospective chart review was conducted on-site in November 2022. The NRC is located on the outskirts of Antigua, Guatemala. They manage the care of 15–20 children at a time, providing food, medicine, and health assessments. A total of 156 records were included (126 prior to the onset of COVID; 30 after the onset of COVID). Descriptive variables collected were age, gender, severity of malnutrition, height, weight, amoxicillin, multivitamins, nebulizer/bronchodilator, and zinc. Principal resultsThere was no significant difference in time-to-recovery between COVID cohorts. Mean time-to-recovery was 5.65 weeks, or 39.57 days (SD = 25.62, 95% CI [35.5, 43.7]) among all recovered cases (n = 149). The cohort admitted after the onset of COVID-19 (March 1, 2020) had a significantly higher weight gain and discharge weight. In the total sample, amoxicillin was the only significant predictor variable for recovery time; with children receiving it being more likely to recover in >6 weeks. The few differences between cohorts was possibly attributed to the sample after the onset of COVID-19. These records had minimal sociocultural data. Major conclusionsConducting a family needs assessment on admission could identify sociocultural factors that may facilitate nutritional recovery, such as housing conditions and potable water access. Further research is needed to more fully understand the complexities that the COVID-19 pandemic has had on childhood malnutrition recovery.

POI Symbol Design in Web Cartography—A Comparative Study

This paper studies the design of point symbols on widely used online maps and apps that portray tourist points of interest (POIs). Tourist maps are among the most commonly used types of maps nowadays. The ease of travel leads to an ever-increasing demand for tourist maps. Therefore, appropriate map design, content and technical means are necessary for better information transfer and communication between the map and the user. Online maps and apps were selected according to specific criteria (e.g., language, geographic area, pictographic symbols, interactivity). Pictographic point symbols for POIs related to tourism activities were collected and described by variables. The frame and the pictogram of the point symbols were the two main directions for choosing the descriptive variables. Description is based on the cognitive scheme for interpretation of cartographic symbols with some improvements. The study reveals the characteristics of the point symbols and constitutes a documentation of the applied practices. The main trends prevalent in the design of these symbols are highlighted and commented on in relation to traditional cartographic practices and guidelines for the design of point symbols.

Implementing and tuning machine learning-based models for description of solubility variations of nanomedicine in supercritical solvent for development of green processing

Determination of drug solubility in supercritical solvents such as CO2 has been of great importance for preparation of nanomedicines. This study implements and tunes several machine learning models to describe the solubility of medicine and density of solvent at various pressure and temperature. The dataset used in this study consisted of the input variables, temperature, and pressure. The methods of AdaBoost algorithm to boost the performance of base regression models for predicting the mole fractions of rivaroxaban and the density of SC-CO2 were developed. The base models used include Theil-Sen Regression (TSR), Gaussian Process Regression (GPR), Automatic Relevance Determination Regression (ARD), and Linear Regression (LR). We employ the Hunter-Prey Optimization technique to tune the hyper-parameters of these models. The results indicated that the boosted models outperform their base counterparts. For the mole fraction predictions, AdaBoost with ARD achieves an R2 value of 0.95986, while AdaBoost with GPR obtains an R2 score of 0.99817. For the SC-CO2 density predictions, AdaBoost with GPR achieves an impressive R2 of 0.99906. Accordingly, the AdaBoost with GPR is the best model for both outputs. These results demonstrate AdaBoost strength and Hunter-Prey algorithm in enhancing the predictive accuracy of regression models for these chemical properties.

Sunlight-directed fluorophore-switch in photosynthesis of cyanine subcellular organelle markers for bio-imaging

The photoconvertible fluorophore synthesis enables the light controlled imaging channels switch for accurate tracking the quantity and localization of intracellular biomolecules in chemical biology. Herein, we repurposed the photochemistry of Fischer's base and developed a sunlight-directed fluorophore-switch strategy for high-efficiency trimethine cyanine (Cy3.5/Cy3) synthesis. The unexpected sunlight-directed photoconversion of Fischer's base proceeds in conventional solvents and accelerates in chloroform via photo-oxidation and hydrogen atom transfer without using extra additives, and the heterogenous dimerization mechanism was proposed and confirmed by isolation of the reactive intermediates. The reliable strategy is employed in the photosynthesis of commercially available cytomembrane marker (DiI) and other cyanine based organelle markers with appreciable yields. Sunlight-controlled fluorophore-switch of subcellular organelle markers in living cells validated the feasibility of our strategy with cell-tolerant character. Moreover, remote control synthesis of Cy3.5 in vivo directed via sunlight further demonstrated the extended application of our strategy. Therefore, this sunlight-directed strategy will facilitate exploitation of cyanine-based probes with switched fluorescence imaging channels and further enable precise description of the dynamic variations in living cells with minimal autofluorescence and cellular disturbance.

Project Risk Management Practices and Performance of Construction Projects: A Case of Horizon Construction in Kigali, Rwanda

The general objective was to examine the effect of project risk management on performance of construction of rehabilitation house construction in Kigali, Rwanda. The specific objectives were; to determine effect of project risk assessment, project risk base decision and project contingency decision on performance of commercial rehabilitation in Kigali. Working on that topic would provide a better way to large-scale construction projects. Other scholars who would be interested to work in the same field. The study used relevant theories such as risk management and risk assessment theories. This research used a descriptive study variables, indicators and measurement. A correlation study design was used to establish the association between variables and regression effect size for each specific objectives. The study targeted 180 staffs of Horizon Construction.&nbsp; A sample of 125 respondents determined using Yamane formula participated in the study process. The sample size was chosen using simple random and purposive sampling techniques. The study collected data using questionnaire and interview guide. The researcher study data using a computer based software known statistical product and service solutions to 26.0 to generate descriptive and inferential statistics. Qualitative data was analyzed using content analysis through themes and subthemes. Findings show that 57.3% show a disagreement with the analysis of risk was the focus at rehabilitation houses construction. Estimating risk given to respondents where 68.3% a positive agreement with the statement. Review technique was agreed by 85.5%. The study discovered that after having an interview with the rehabilitation houses construction. The study results show that 59.3 at a mean of 3.63 and standard deviation of 1.135 demonstrated an agreement that Horizon Construction applied managing change orders, 66.7% evidence that Horizon Construction has poorly written contact. Moreover, 63.4% accepted that the statement that Horizon Construction felt that all customers were given a time of allocation of decision and 65.4 agreed that the Horizon Construction prepared how they are managing decision with a mean of 4.18 and standard deviation of 1.14. Findings reiterate that 56.8% accepted that program management, 57.8% indicated that Horizon Construction was the implementation a mean&nbsp; of 4.13 and standard deviation&nbsp; of 1.37, 74.0% confirmed the used of program improvement with a mean&nbsp; of 1.85 and standard deviation&nbsp; of 1.28. The study recommends that the need of careful project risk management or availing the supervisor of construction work to be sure with the completion of project on time with timely. Result will minimize the effect of challenges and seizure of change that appear. The study proposed the Horizon&nbsp; Ltd to avail supervisory activities toward construction project or being sure that managing risks should comprise the preventive techniques or meeting the due date and effective use of resources. Benefits of risk management in projects are huge. Keywords: Project Risk Management Practice, Risk Base Decision, Contingency Decision, Performance of Construction, Construction of Rehabilitation Houses